The subject matter disclosed herein relates to machine shafts and, more particularly, to a system for electrically grounding rotating shafts in machines, particularly dynamoelectric machines.
Some machines (e.g., dynamoelectric machines, generators, alternating current motors, direct current motors etc.) and/or apparatuses, employ rotary shafts in their design and operation. These rotary shafts may be physically connected to portions of the machine and supported by bearings. In operation, some of these shafts may develop and/or receive unwanted electrical voltages. These voltages may discharge from the shaft through portions of the machine (e.g., bearings), causing fusion craters, severe pitting, fluting damage, bearing failure, etc. Therefore, it is desirable to preemptively dissipate and/or release these unwanted electrical voltages in a controlled manner, thereby avoiding damage to machine components. Some machines use grounded brush seals and/or carbon fibers disposed around and physically in contact with the rotary shaft to ground the unwanted electrical voltages. These systems are machined to fit precisely about the shaft and include conductive elements which are physically in contact with both the rotating shaft and an electrically grounded component. However, these systems may require special machining to attain a proper fit, and as a result of the requisite physical contact may wear, degrade, produce dust and generate sparks during operation.